OBJECTIVES: To assess vaccine effectiveness (VE) and safety of the recombinant zoster vaccine (RZV) in adults with systemic lupus erythematosus (SLE).
METHODS: This retrospective study using administrative claims data collected between 1 January 2018 and 30 September 2023 from the USA included two cohorts of adults aged ≥ 18 years with SLE insured by (1) Medicare (parts A/B/D) or (2) one of five commercial partners (including Medicare Advantage plans). In VE analyses, adults receiving two RZV doses ≥ 28 days apart were matched 1:4 to unvaccinated comparators on insurer, sex and age (±5 years); the outcome was incident herpes zoster (HZ) after 31 days. In safety analyses, adults receiving RZV dose 1 or 2 were matched to unvaccinated comparators as above; the outcome was severe SLE flare within 90 days. Adjusted hazard ratios (HRs) were estimated using Cox models with inverse probability of treatment weighting (IPTW).
RESULTS: VE cohorts included 2284 Medicare and 1308 commercially insured RZV-vaccinated patients; mean weighted follow-up was 1.4-1.6 person-years. Safety cohorts included 6602 RZV vaccinations (dose 1 or 2) in Medicare and 4196 in commercial insurers. Vaccinated versus unvaccinated patient characteristics were balanced after IPTW. VE was 70% (95% CI: 50% to 82%) in Medicare and 54% (95% CI: 18% to 74%) in commercially insured patients. The HR of severe SLE flare in vaccinated versus unvaccinated patients was 0.91 (95% CI: 0.75 to 1.11) in Medicare and 0.94 (95% CI: 0.72 to 1.24) in commercially insured patients.
CONCLUSIONS: RZV prevented a majority of HZ cases in individuals with SLE without increasing the risk of severe SLE flare.